1. Field of the Invention
In general, the present invention relates to systems and methods that are used to install or repair overhead doors. More particularly, the present invention relates to systems and methods that can be used to install or repair overhead rolling doors that wind about a central axle.
2. Prior Art Description
Many businesses and some homes have overhead rolling doors. An overhead rolling door has a door typically made of interconnected metal segments. The segments are affixed to a suspended axle that is mounted over a door opening. When the door is open, the metal segments are wound around the axle in the same manner as a window shade. When the door is closed, the metal segments are unwound from the axle and are extended to the ground.
An overhead rolling door can weigh hundreds, even thousands, of pounds depending upon the size and strength of the door. For large overhead doors, the door is typically raised and lowered using an electric motor or a pulley chain. However, for smaller overhead doors, such as those used over windows and the access doors of self-storage facilities, the overhead door contains counterbalance springs. When the overhead door is pulled closed, energy is stored in the counterbalance springs. This energy acts to bias the overhead door into its retracted open position. As a result, when a person opens the overhead door, the energy stored in the counterbalance springs assists in the opening process even a small person is capable of lifting a door that may weigh hundreds of pounds.
A problem that commonly occurs in such counterbalance systems is that the counterbalance springs often need replacement due to breakage and/or metal creep. The counterbalance springs store energy for as long as the door is closed. In many scenarios, such doors can be closed for days, weeks, and even years at a time. In other scenarios, the doors may be opened and closed many times in one day, therein exposing the counterbalance springs to thousands of work cycles in a given year. Both scenarios eventually lead to the failure of the counterbalance springs.
When a counterbalance spring in an overhead rolling door assembly needs replacement, special skills and special equipment are required for the repair. In the prior art, the entire rolling door assembly is typically removed from above a door and lowered to the ground. Since the rolling door assembly may weigh many hundreds of pounds, the removal of the rolling door assembly typically requires the use of at least two men or a forklift or similar piece of heavy lifting equipment. Once the rolling door assembly is lowered to the ground, the rolling door assembly is disassembled. The damaged spring is repaired. The replacement counterbalance spring is tensioned by manually rolling the door back onto its axle. The overhead rolling door assembly is then put back together, lifted back into place and reinstalled. It will therefore be understood that the repair of a counterbalance spring in an overhead rolling door is a very time consuming and labor intensive endeavor.
In the prior art, jigs, lifts and other specialized devices used to install doors of different types are common. Consider for example, U.S. Pat. No. 7,780,389 to Young, entitled Door Installation System and U.S. Pat. No. 4,278,244 to Carter, entitled Pivotable Dolly For Holding Transporting And Hanging A Door. However, none of the prior art devices are designed to simplify the most common repair to an overhead rolling door assembly.
A need therefore exists for a system and method that enables a counterbalance spring within an overhead rolling door to be rapidly and simply repaired, so as to greatly reduce the time, labor and expense required to make such a repair. This need is met by the present invention as described and claimed below.